In order to maximize efficiency of limited radio resources, an effective transmission and reception scheme and various methods of utilization thereof have been proposed in a broadband wireless communication system. A carrier aggregation system is one of systems considered in a next-generation wireless communication system. The carrier aggregation system implies a system which supports a broadband by aggregating one or more carriers having a bandwidth narrower than that of a desired broadband when a wireless communication system intends to support the broadband.
A wireless communication system such as conventional 3rd generation partnership project (3GPP) long term evolution (LTE) uses a carrier of various bandwidths, but is a single-carrier system which uses one carrier. Meanwhile, a next-generation wireless communication system such as LTE-advanced (A) may be a multiple-carrier system which aggregates multiple carriers, that is, which uses carrier aggregation.
The single-carrier system (e.g., LTE) uses a single-carrier property to effectively use a power amplifier of a user equipment (UE) in an uplink in which the UE transmits a signal to a base station (BS). A control region for transmitting control information and a data region for transmitting data are distinctively used by the UE. To maintain a single-carrier property, signals are not simultaneously transmitted in the control region and the data region.
On the other hand, the carrier-aggregation system (e.g., LTE-A) may or may not allow simultaneous transmission of the control region and the data region according to a configuration. If the carrier aggregation system does not allow the simultaneous transmission of the control region and the data region, there may be a case where the UE must transmit channel status information together with data at a specific time. In this case, the UE may transmit the channel status information together with the data in the data region, which is expressed that the channel status information is transmitted in a piggyback (or multiplexing) manner. If the channel status information is piggybacked in the data region, the resource region on which data is intended to be carried is punctured, and thus the channel status information is transmitted by using the punctured region. Alternatively, rate matching is performed. That is, if the channel status information is piggybacked, the data of the data region is transmitted differently from a case where the channel status information is not piggybacked.
Piggyback transmission of the channel status information is performed only for an activated carrier, and is not performed for a deactivated carrier. However, an activation/deactivation state for a specific carrier may be incorrectly recognized between the BS and the UE. In this case, channel status information for a carrier unexpected by the BS may be transmitted in a piggyback manner. Therefore, a problem may arise in that the BS fails to properly decode the data included in the data region.